Asian Race and Primary Open-Angle Glaucoma: Where Do We Stand?

Does Bevacizumab Improve Outcomes After Ahmed Glaucoma Valve Implantation for Refractory Glaucoma?: A Meta-Analysis

PRCIS

Mean intraocular pressure (IOP), complete and overall success, mean IOP-lowering medications, incidence of hypertensive phase, and complications were found to be comparable between patients undergoing Ahmed glaucoma valve implantation (AGVI) with adjunctive bevacizumab versus AGVI alone.

OBJECTIVE

This meta-analysis aims to assess how adjunctive bevacizumab impacts the surgical outcomes of AGVI compared with AGVI alone in all subtypes of refractory glaucoma.

METHODS

A systematic search of databases for relevant randomized controlled trials (RCTs) was performed in March 2023. Primary outcomes included mean IOP and success rates. Secondary outcomes were mean IOP-lowering medications, incidence of hypertensive phase, and complications. Qualitative assessment, meta-analysis, subgroup analyses, and sensitivity analysis were performed.

RESULTS

Five RCTs comprising 203 eyes were included in the quantitative analysis. Initial meta-analysis showed a strong yet nonsignificant trend (all P > 0.05) favoring adjunctive bevacizumab in all outcomes of interest. Significant heterogeneity was observed for mean IOP and success outcomes at all time points (all I2 > 50%). Subgroup analysis of the administration route revealed a reduced incidence of hyphaema in the intravitreal bevacizumab subgroup (odds ratio: 0.10; 95% CI: 0.02 to 0.59; P = 0.01) with significant heterogeneity persisting in the intravitreal bevacizumab subgroup for all measures (all I2 > 50%). Post hoc sensitivity analysis of studies without concurrent pan-retinal photocoagulation for mean IOP and success outcomes demonstrated more conservative effect sizes with a corresponding decrease in heterogeneity for all measures (all I2 < 30%).

CONCLUSION

Published studies investigating the role of adjunctive bevacizumab show a strong trend to improve outcomes but contain a relatively small number of participants. This analysis underpins the need for an adequately powered RCT to explore the role of anti-vascular endothelial growth factor agents in AGVI surgery.

Predictors of Glaucomatous Progression in Individuals with Small and Large Optic Discs

PURPOSE

To identify factors associated with glaucomatous progression in individuals with small and large optic discs.

DESIGN

Retrospective review.

SUBJECTS

4505 individuals with glaucoma at UCLA; 233 (59.7%) with small discs, 157 (40.3%) with large discs.

METHODS

Small and large disc sizes were defined by OCT or Heidelberg Retinal Tomography as disc area ≤ 5% (≤ 1.3 mm2) and ≥ 95% (≥ 2.9 mm2), respectively. Medical records were reviewed for demographics, systemic comorbidities, glaucoma type, ocular comorbidities, and ocular surgery. Logistic regression was used to identify predictors of visual field (VF) progression in individuals with small and large discs and predictors of large versus small discs.

MAIN OUTCOME MEASURES

The VF deterioration with mean deviation, pointwise linear regression, and glaucoma rate index (GRI); large vs. small disc.

RESULTS

In individuals with small discs, Asian versus non-Hispanic White ethnicity was associated with increased progression (adjusted odds ratio [aOR] = 4.05; 95% confidence interval [CI] = 1.12-14.59 for GRI). Higher intraocular pressure (IOP) range and peak were associated with increased progression in individuals with both small discs (aOR = 1.12; 95% CI = 1.00-1.27 and aOR = 1.05; 95% CI = 1.00-1.10 per 1 mmHg for range and peak with GRI) and large discs (aOR = 1.35; 95% CI = 1.12-1.66 and aOR = 1.11; 95% CI = 1.03-1.20 per 1 mmHg for range and peak with GRI). Multivariable predictors of having large vs. small discs included vasospastic phenotype (aOR = 2.58; 95% CI = 1.35-5.19) and Black (aOR = 20.46; 95% CI = 8.33-61.84), Hispanic/Latino (aOR = 9.65; 95% CI = 4.14-25.39), Asian (aOR = 4.87; 95% CI = 2.96-8.1), and other (aOR = 2.79; 95% CI = 1.69-4.63) versus non-Hispanic White ethnicity.

CONCLUSIONS

Increased odds of glaucomatous progression were associated with Asian vs. non-Hispanic White ethnicity in glaucoma patients with small optic discs, as well as with increased IOP range and peak in those with small and large discs. Individuals with a vasospastic phenotype and those from racial and ethnic minority backgrounds had increased odds of having large vs. small optic discs. Further characterization of discernible phenotypes would improve disease prognostication and help individualize glaucoma treatment.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Inhibition of TGF-β2-Induced Trabecular Meshwork Fibrosis by Pirfenidone

Purpose

Trabecular meshwork (TM) fibrosis is a crucial pathophysiological process in the development of primary open-angle glaucoma. Pirfenidone (PFD) is a new, broad-spectrum antifibrotic agent approved for the treatment of idiopathic pulmonary fibrosis. This study investigated the inhibitory effect of PFD on TM fibrosis and evaluated its efficacy in lowering intraocular pressure (IOP).

Methods

Human TM cells were isolated, cultured, and characterized. Cell Counting Kit-8 was used to evaluate the proliferation and toxicity of different concentrations of PFD on normal or fibrotic TM cells. TM cells were treated with transforming growth factor beta-2 (TGF-β2) in the absence or presence of PFD. Western blotting and immunofluorescence analyses were used to analyze changes in the TM cell cytoskeleton and extracellular matrix (ECM) proteins, including alpha-smooth muscle actin (α-SMA), F-actin, collagen IV (COL IV), and fibronectin (FN). An ocular hypertension (OHT) mouse model was induced with Ad-TGF-β2C226/228S and then treated with PFD or latanoprost (LT) eye drops to confirm the efficacy of PFD in lowering IOP.

Results

PFD inhibited the proliferation of fibrotic TM cells in a dose-dependent manner and inhibited TGF-β2-induced overexpression of α-SMA, COL IV, and FN in TM cells. PFD stabilized F-actin. In vivo, PFD eye drops reduced the IOP of the OHT models and showed no significant difference compared with LT eye drops.

Conclusions

PFD inhibited TGF-β2-induced TM cell fibrosis by rearranging the disordered cytoskeleton and decreasing ECM deposition, thereby enhancing the aqueous outflow from the TM outflow pathway and lowering IOP, which provides a potential new approach to treating glaucoma.

Translational Relevance

Our work with pirfenidone provides a new approach to treat glaucoma.

Metabolic syndrome as an independent risk factor for glaucoma: a nationally representative study

BACKGROUND

Central insulin resistance contributes to glaucoma development. Given the close association between metabolic syndrome MetS and insulin resistance, this study aimed to determine whether MetS is associated with glaucoma risk.

METHODS

We analyzed data from 11,499 adults aged ≥ 19 years in the 2019-2021 Korean National Health and Nutrition Examination Survey and applied sampling weights to represent the general Korean population. Participants were classified into groups with or without MetS. Ocular hypertension (HTN) was defined as intraocular pressure > 21 mmHg. Primary open-angle glaucoma (POAG) was diagnosed based on the results of a visual field test and optical coherence tomography using the criteria published by the International Society for Geographic and Epidemiological Ophthalmology. We further divided POAG into normal tension (NTG) and POAG with ocular HTN. A spline curve was drawn to determine the dose-response relationship between the number of MetS components and risk of POAG. Odds ratios (ORs) with 95% confidence interval (CI) for POAG according to MetS status were estimated using weighted logistic regression analyses.

RESULTS

The prevalence of POAG was 5.7% and 3.5%, respectively, in groups with and without MetS. We identified a dose-response relationship between the number of MetS components and risk of POAG. Unadjusted ORs (95% CI) for POAG in the group with MetS was 1.85 (1.52-2.25), compared with those without MetS. The trends persisted in adjusted models. The fully-adjusted OR (95% CI) for POAG was 1.47 (1.04-2.09) in the group with MetS. Subgroup analysis revealed that a significant relationship remained only in the NTG group (fully adjusted OR, 1.50; 95% CI 1.05-2.15).

CONCLUSIONS

A comprehensive ophthalmological assessment should be considered for persons with MetS who are at increased risk of POAG, particularly NTG.

Immunomodulatory and Antioxidant Drugs in Glaucoma Treatment

Glaucoma, a group of diseases characterized by progressive retinal ganglion cell loss, cupping of the optic disc, and a typical pattern of visual field defects, is a leading cause of severe visual impairment and blindness worldwide. Elevated intraocular pressure (IOP) is the leading risk factor for glaucoma development. However, glaucoma can also develop at normal pressure levels. An increased susceptibility of retinal ganglion cells to IOP, systemic vascular dysregulation, endothelial dysfunction, and autoimmune imbalances have been suggested as playing a role in the pathophysiology of normal-tension glaucoma. Since inflammation and oxidative stress play a role in all forms of glaucoma, the goal of this review article is to present an overview of the inflammatory and pro-oxidant mechanisms in the pathophysiology of glaucoma and to discuss immunomodulatory and antioxidant treatment approaches.

Association Between Risk of Obstructive Sleep Apnea and Glaucoma: The Singapore Epidemiology of Eye Diseases Study

PRCIS

In this population-based, cross-sectional study of Indian and Malay adults in Singapore aged 40 years or above, intermediate or high risk of obstructive sleep apnea (OSA) was associated with 50% higher odds of having glaucoma.

BACKGROUND/AIMS

The relationship between OSA and glaucoma is unclear. We assessed the association between the risk of OSA and glaucoma in an Asian population.

MATERIALS AND METHODS

In this population-based, cross-sectional study, we included Indian and Malay adults aged 40 years or above recruited between 2011 and 2015. Glaucoma was assessed by trained ophthalmologists and classified into primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG). OSA risk was assessed with the Snoring, Tiredness, Observed apnea, High blood pressure, Body mass index, Age, Neck circumference, and male Gender (STOP-Bang) questionnaire and categorized as low risk (<3) or intermediate/higher risk (≥3). We used multivariable logistic regression models to evaluate the relationship between risk of OSA and glaucoma adjusted for key variables, and further stratified for subtype and ethnicity.

RESULTS

Of the 3126 participants (mean age: 63.1±9.6 y; 52.5% female), 134 (4.3%) had glaucoma, comprising 86 (2.8%) POAG, 22 (0.7%) PACG and 26 (0.8%) secondary glaucomas, and 1182 (37.8%) had an intermediate/higher risk of OSA. Compared with individuals with a low risk of OSA, individuals with intermediate/higher risk had 50% greater odds of having glaucoma (odds ratio: 1.55, 95% confidence interval: 1.03-2.33; P =0.035). We observed a nonsignificant increase in likelihood of having POAG in those with intermediate/higher risk of OSA compared with those with low risk. The OSA-glaucoma relationship was modified by ethnicity, with Malays with intermediate/higher risk of OSA having a 2-fold risk of having any glaucoma (odds ratio: 2.01, 95% confidence interval: 1.12-3.59 P =0.019); while the same elevated risk was not observed for Indians.

CONCLUSIONS

Intermediate or high risk of OSA is associated with 50% higher odds of having glaucoma in our Singaporean population, with a 2-fold higher risk of glaucoma observed in Malays (but not Indians); however a conformational sleep study is needed.